After pushback from gate, I parked the brakes per tug driver request. I then started the right engine and notified driver that the start was complete and cleared to disconnect. While waiting for a salute, the driver called to tell me the brakes were not parked as aircraft was rolling slowly forward. I immediately stopped the forward motion and set the brakes. There were no unusual distrs during the entire process and I do not know if I had set the brakes and then released them or had never set them. I asked the driver if everything was ok, which it was, and I proceeded to taxi out. This event occurred on the 6TH day in a row of flying (I am on reserve) and I feel that fatigue was a major factor. The cumulative effects of reassignments, a diversion, cancellations and a late night arrival, while all legal, proved to be too much. Upon arrival at destination, crew schedule called to reassign me to continue flying. I declined due to fatigue.

Title: AN MD80 CAPT CITED FATIGUE AS THE REASON HE IMPROPERLY SET HIS BRAKES BEFORE PUSHBACK AT AUS.

Narrative: AFTER PUSHBACK FROM GATE, I PARKED THE BRAKES PER TUG DRIVER REQUEST. I THEN STARTED THE R ENG AND NOTIFIED DRIVER THAT THE START WAS COMPLETE AND CLRED TO DISCONNECT. WHILE WAITING FOR A SALUTE, THE DRIVER CALLED TO TELL ME THE BRAKES WERE NOT PARKED AS ACFT WAS ROLLING SLOWLY FORWARD. I IMMEDIATELY STOPPED THE FORWARD MOTION AND SET THE BRAKES. THERE WERE NO UNUSUAL DISTRS DURING THE ENTIRE PROCESS AND I DO NOT KNOW IF I HAD SET THE BRAKES AND THEN RELEASED THEM OR HAD NEVER SET THEM. I ASKED THE DRIVER IF EVERYTHING WAS OK, WHICH IT WAS, AND I PROCEEDED TO TAXI OUT. THIS EVENT OCCURRED ON THE 6TH DAY IN A ROW OF FLYING (I AM ON RESERVE) AND I FEEL THAT FATIGUE WAS A MAJOR FACTOR. THE CUMULATIVE EFFECTS OF REASSIGNMENTS, A DIVERSION, CANCELLATIONS AND A LATE NIGHT ARR, WHILE ALL LEGAL, PROVED TO BE TOO MUCH. UPON ARR AT DEST, CREW SCHEDULE CALLED TO REASSIGN ME TO CONTINUE FLYING. I DECLINED DUE TO FATIGUE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.